Skin Infections in Pregnant Women: Many Drugs Safe, but Not All

Randy Dotinga

SAN DIEGO — Multiple topical and systemic medications are safe for treating pregnant women with bacterial, viral, and fungal infections, a dermatologist told colleagues at the annual meeting of the American Academy of Dermatology. However, several drugs should be avoided or used with caution because of potential risks during pregnancy. 

When treating bacterial infections in pregnant women, there are many options, "especially for the sort of short-term antibiotic use that we tend to use for treating infections," said Jenny Murase, MD, of the Palo Alto Foundation Medical Group and the University of California San Francisco.

During a presentation on treating infections in pregnant patients, she made the following recommendations for treating pyogenic infections: 

  • Impetigo: First-line treatments are topical mupirocin (Bactroban, Centany), oral first-generation cephalosporins, and oral dicloxacillin.
  • Cellulitis: Recommended treatments are oral or intravenous penicillin, oral first-generation cephalosporins, and oral dicloxacillin.
  • Methicillin-resistant Staphylococcus aureus ( MRSA): "Clindamycin is first-line, dependent on bacteria culture and sensitivities," and because of its safety, "it's a really good choice for a pregnant woman." Murase said. However, be aware of potential inducible resistance and test for the erm gene, she said.
  • Abscesses: Incision and drainage are recommended. "Whenever we're managing a patient with a condition during pregnancy, we want to try to use nonmedications when possible," Murase said. "No antibiotic is necessary unless the abscess is greater than 5 cm or if it's greater than 2 cm with erythema around the abscess."
  • Tuberculosis: The best strategy is rifampin (Rifadin), but peripartum vitamin K prophylaxis for mother and fetus should be used, she said. 

General Infections

With regards to antibiotics to treat general infections — for instance, if a patient with atopic dermatitis has a secondary skin infection — Murase recommended first-line oral antibiotic therapy with penicillin, first-generation cephalosporins, or dicloxacillin. For second-line therapy, erythromycin is the preferred macrolide over azithromycin (Zithromax) and clarithromycin, she said. 

Murase noted that there is an increased risk for atrial/ventricular septal defects and pyloric stenosis associated with the use of erythromycin when used during the first trimester of pregnancy. In addition, erythromycin estolate increases the risk of liver toxicity, while erythromycin base and erythromycin ethylsuccinate do not. 

Sulfonamides are a second-line line choice up until the third trimester. If given to a patient in the first trimester, she said, "make sure that they are supplementing with folic acid efficiently, at least 0.5 mg a day." During the peripartum period they are contraindicated, as they pose a risk for hemolytic anemia, hyperbilirubinemia, and kernicterus. 

The combination drug trimethoprim/sulfamethoxazole (Bactrim, Sulfatrim) is a second-line choice for complicated infections because of the associated risk for low birth weight and prematurity, Murase said.

Quinolones are also a second-line option during pregnancy she said, and ciprofloxacin (Cetraxal, Cipro) and norfloxacin (Noroxin) have been studied the most. "If you have to choose a quinolone for a complicated infection in pregnancy, those would be the quinolones of choice," Murase said.

Considering the bad reputation of tetracyclines in pregnancy, dermatologists may be surprised to learn that they are considered a second-line therapy up to 14 weeks' gestation, she said. After that time, however, they're contraindicated because of bone growth inhibition, teeth discoloration, and maternal hepatitis.

Fungal Infections

As for fungal infections, clotrimazole (Lotrimin) is the first treatment choice for topical treatment of tinea corporis, followed by miconazole and then ketoconazole (Nizoral, Xolegel, Extina), according to Murase. There are limited data for topical terbinafine (Lamisil), naftifine (Naftin), and ciclopirox during pregnancy she noted, but they are likely safe.

There is also limited data about these drugs when used for topical treatment of candidiasis during pregnancy. Nystatin (Nyamyc, Nystop, Nyata) is safe, but less effective than other options, Murase said. Other options include clotrimazole, miconazole, and ketoconazole, which, in animals exposed to high doses, have not been associated with defects, and topical gentian violet (0.5%-1% solution), she noted.

For topical treatment of tinea versicolor during pregnancy, limited application of clotrimazole or miconazole is considered safe, and zinc pyrithione soap or topical benzoyl peroxide soap can be used for more widespread areas. 

Murase recommended caution when using selenium sulfide (Selsun Blue, SelRx, Tersi) since poisoning has been linked to miscarriages, she said. Limited application appears to be safe, "so make sure that the patient is using it on smaller body surface areas."

As for systemic antifungal treatments, fluconazole (Diflucan), ketoconazole (Nizoral, Xolegel, Extina), and itraconazole (Sporanox, Onmel) should be avoided in pregnancy because of the risks of craniosynostosis, congenital heart defects, and skeletal anomalies, Murase said. However, she referred to a study that found no increased risk of congenital malformations with fluconazole during the first trimester, and a patient could be reassured if, for example, she was treated for a yeast infection before she knew she was pregnant, she said. 

Griseofulvin is not recommended during pregnancy, but a 2020 study suggests that terbinafine is safe, she said. In that study, oral or topical terbinafine did not appear to be associated with an increased risk for spontaneous abortion or major malformations. "Certainly, we can wait until after the pregnancy to treat onychomycosis. But I have had situations that even in spite of regular topical therapy, pregnant patients needed to take some kind of oral agent" because of severe itching. 

Viral Infections

For herpes simplex, acyclovir (Sitavig, Zovirax) is the top choice, and famciclovir and valacyclovir (Valtrex) are likely safe, but daily prophylaxis is not recommended during pregnancy, Murase said. 

Because of a lack of data, podofilox (Condylox), cantharidin, and imiquimod (Zyclara, Aldara) for treating human papillomavirus (HPV) should be avoided, she said. Podophyllin is extremely dangerous in pregnancy and has been linked to maternal and fetal deaths, and malformations, and is contraindicated in pregnancy, she added.

Instead, liquid nitrogen is the treatment of choice for HPV in pregnant patients, she said. 

Trichloracetic acid is the treatment of choice for condylomata acuminata, and squaric acid or intralesional Candida antigen injection for periungual verrucas can be used, she said, and limited applications of salicylic acid are considered safe. 

Murase highlighted a 2014 paper that she co-authored on the safety of dermatologic medications during pregnancy, noting that an updated report will be published later this year.

Murase disclosed relationships with Regeneron and UCB (speaker), Sanofi/Regeneron and Bristol-Myers Squibb (advisory board), and UCB, AbbVie, and UpToDate (consulting). 

Randy Dotinga is an independent medical journalist and board member of the Association of Health Care Journalists. 

 

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